1/.st thing for me would be to measure the bore and groove diameter.
I would then determine what size ball and thickness of patch I needed to reach the bottom of the grooves.
2/.nd would be to select a mould that cast the size ball I needed - likely from Buffalo Arms, or Track or some
other outfit - if odd size needed I'd look no further than Jeff Tanner moulds. Jeff's widow and son could use the business.
Then varying loads from about 85gr.2F lightest up to about 140gr.2F for highest in determining the most accurate loads for that barrel & rifle - for
hunting and target. Hunting with oiled or greased patch, water based for target shooting. Note oiled or greased patches will
likely not shoot to the same POI as water based lubes.
With a good combination for hunting or target, you should not have to wipe between shots - or after 3, 5 or 25- UNLESS - there is a long time between your shots, like 5 to 10 minutes or more.